IN­NO­VA­TION NOTE­BOOK

Pow­er­ful, but risky, clot-bust­ing drugs are not needed by all pa­tients with blood clots in their legs, Hamil­ton re­searchers have con­cluded. Clear­ing the clot with med­i­ca­tion and spe­cial­ized de­vices did not re­duce the risk of a com­pli­ca­tion known as post-throm­botic syn­drome, which can leave pa­tients with longterm leg pain and swelling that leads to dif­fi­culty walk­ing. But it in­creased the chances of a dan­ger­ous bleed, re­veals the study by re­searchers at McMaster Uni­ver­sity, Hamil­ton Health Sciences and led by Washington Uni­ver­sity, Mas­sachusetts Gen­eral Hos­pi­tal and St. Luke’s MidAmer­ica Heart In­sti­tute in Kansas City. The ben­e­fits may still out­weigh the risks for some deep vein throm­bo­sis pa­tients, par­tic­u­larly those with ex­cep­tion­ally large clots, found the re­search pub­lished Thurs­day in the New Eng­land Jour­nal of Medicine. The Acute Ve­nous Throm­bo­sis: Throm­bus Re­moval with Ad­junc­tive Catheter-Di­rected Throm­bol­y­sis (AT­TRACT) study ran­dom­ized 692 pa­tients to re­ceive blood thin­ners alone, or the drugs plus a pro­ce­dure, and fol­lowed them for two years. The study had a num­ber of fun­ders, in­clud­ing the Na­tional Heart, Lung and Blood In­sti­tute in the United States, Washington Uni­ver­sity’s Cen­ter for Trans­la­tional Ther­a­pies in Throm­bo­sis and Washington Uni­ver­sity’s In­sti­tute of Clin­i­cal and Trans­la­tional Sciences. It also re­ceived sup­port from in­dus­try, in­clud­ing Bos­ton Sci­en­tific, Co­vi­dien (now Medtronic), Ge­nen­tech and BSN Med­i­cal.

Spinal tap

The nee­dle used dur­ing a spinal tap makes a big dif­fer­ence in de­creas­ing headaches, nerve ir­ri­ta­tion and hear­ing dis­tur­bance in pa­tients, found a Hamil­ton study. The pen­cil-point atrau­matic nee­dle re­duced headaches, emer­gency room vis­its and hos­pi­tal read­mis­sion af­ter lum­bar punc­tures, by more than 50 per cent, concludes the re­search pub­lished Wed­nes­day in the Lancet. But it costs up to three times more than the nor­mally used beveled trau­matic nee­dles. The atrau­matic nee­dle has been around for about 70 years, but few doc­tors use it be­cause they don’t know it can sig­nif­i­cantly de­crease com­pli­ca­tions, say the re­searchers from Hamil­ton Health Sciences and McMaster Uni­ver­sity. It’s sig­nif­i­cant con­sid­er­ing spinal taps used to di­ag­nose and treat dis­ease can cause headaches in about one-third of pa­tients, some­times caus­ing de­bil­i­tat­ing pain. The dif­fer­ence is how the two types of nee­dles pen­e­trate the thick mem­brane sur­round­ing the nerves, called the dura. The con­ven­tional nee­dle cuts its way through, while the tip of the atrau­matic nee­dle causes the tis­sue to di­late and con­tract around it, leav­ing a tiny hole that sig­nif­i­cantly re­duces the chance of cere­brospinal fluid leak­ing through. The study used no ex­ter­nal fund­ing and pooled data from 30,000 pa­tients in 110 clin­i­cal tri­als done in 29 coun­tries.

Treat­ing cys­tic fi­bro­sis

A Hamil­ton re­searcher is get­ting just over $280,000 to im­prove per­son­al­ized treat­ment for cys­tic fi­bro­sis pa­tients. Dr. Jeremy Hirota, of St. Joseph’s Health­care, was awarded a New In­ves­ti­ga­tor Re­search Grant to cre­ate a tool that will work faster to come up with the best com­bi­na­tion of drugs for each pa­tient. The grant given by the Sick­Kids Foun­da­tion, and the Cana­dian In­sti­tutes of Health Re­search, will fo­cus on pre­ci­sion medicine, which works by test­ing com­bi­na­tions of dif­fer­ent drugs. Hirota will com­bine pre­ci­sion medicine with a new tech­nol­ogy called mi­croflu­idics, which is the study of tiny vol­umes of liq­uids. The hope is that the re­sult­ing de­vice will re­quire smaller sam­ples from pa­tients and work faster to find the best com­bi­na­tion of drugs tai­lored to the pa­tient. Cys­tic fi­bro­sis is the most com­mon fa­tal dis­ease af­fect­ing Cana­dian chil­dren and youth.

Genes ‘snow­ball’ obe­sity

Nine genes make you gain more weight if you al­ready have a high body mass in­dex, McMaster Uni­ver­sity re­searchers have re­vealed. “It’s sim­i­lar to a tiny snow ball at a top of a hill that be­comes big­ger and big­ger when rolling down the hill,” David Meyre, an as­so­ci­ate pro­fes­sor who holds the Canada re­search chair in ge­net­ics of obe­sity. He helped au­thor a study look­ing at 37 genes al­ready linked with body mass in­dex and found the nine with the snow­ball effect. “These genes may, in part, ex­plain why some in­di­vid­u­als ex­pe­ri­ence un­con­trolled and con­stant weight gain across their life, de­spite the avail­abil­ity of dif­fer­ent ther­a­peu­tic ap­proaches,” Meyre said. The study of 73,230 adults with Euro­pean an­ces­try was pub­lished Thurs­day in the Amer­i­can Jour­nal of Hu­man Ge­net­ics.